Subterranean signaling system



L. DE FORHEST. SUBTERRANEAN SIGNALING SYSTEM.

APPLICATION FILED JUNE I6, 1917.

Patented Aug. 8, 1922.

New York, in the' [st-rares' ortica.

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To allwhomz't may concern: i Be it known that l, LEE ma'. Fonnsr, 'a citizen ofthe United States, residing at county and State of New York, have made a4 certain new and useiul Invention vin lSubterranean Signalingl Systems, ot which the following 'is a specification.

construction, combination, l

employed, ally ing drawing and inally vpartv This invention relates tosignaling systems and more particularlyto electrical subterranean signaling systems. The object-'of the invention is to provide an electrical subterraneanslgnaling system which is simple in arrangement andv eiicient in operation.

Further objects of the-invention will ap-' pear more' fully hereinafter. f f

The invention consists substantially in the location and relative arrangement o-.palfts,'and the ySystem after set forth, asshown bythe accompanypointed4 out inthe appended claims. z Referring to the drawing;

Fig. l is a diagrammatic vi terranean transmission my invention.

Fig 2 is a similar view'of a 'receiifing'sys-y tem embodying my invention The same @afer the aan;

numeral wherever it occurs'throughout the several views.

Referring to thedrawing': f l designate at earths surface and at'8 a lower stratum -to the stratum 8 20, 21 extend, which lines/are of different conductivity from the' surface stratum, and a considerable distance below the surface 2l show boringsl from the surface down through which the lines provided at their ends with metallicl ,plates or' bodies 3 and 4 respectively which are lowered throughthe wells land 2 and ,make contact with the conducting layer 8. The lines 20 and `21 'extendA lup 'throng A'and are 'in-the form of insulated wire `or cable.

Earth'- plates and 4 are separated by a considerable.distancewhich maybe several miles, or even several hundreds of miles, and are connectedl to each overhead lines or grou of wires 20, 2l, separated by, suitable insu ated poles 2%.

i Spcification of Letters'Patent.

. nating current current. 'thus generated y1n any desiredv manner, Morse key 10, located` in the eld circuitv as will be more-.fully herein- Area ily employed without system embodying l labo've described. .tively little impedance is designated bythe samev reference f vsent out 1n this lmeans of signaling,

7 the. upper stratum'of thej with those'attanedfin radio communication of the earth. At l and` h wells l and 2 other through the Patente many e, ieee.

' Y application mea ma@ 16,1917. serrano. 17ans.

`l represents the transmitting station, as above` outlined and .in the form .shown is a telegraph transmitting station` wherein any suitable source yof current may be employed, such tor example, .as the alterdynamo 9." This generates alternating current preferably of sustained waves andl of frequency low as compared lwith those now' used 1n radio telegraphy,

that is, from 500 to 25,000 per second.' rlhe may be controlled for example, by the l1 of the dynamo.

2While l have shown the ,system as a teleployed Jfor telephone signals, and many of the improved apparatus well known in the art for use in connection with either of the tele vraph or telephone systems,

thescope of my ,invention as defined in' the claims .a f The 'ea'rth'ed circuit is preferably attuned to the generator frequency b suitable means for example, thevariable in uctances 22, 23.

lha-ve' discovered that for the frequencies the earth offers comparaso that relatively large? amounts of energy-are radiated or the form of conduction currents so tha-tf great distances can be covered by comparable even with smaller amounts of energy atthe trans'- mitter.- @By this system lla-menabled to 'avoidffthe interferences caused by atmos! pheric disturbances-which so frequently in- The vproblems of interferences between terrupt aerial radial communication.

earth return system should be tuned to the might be departing from- Gti' i graph system it is obvious that with but slight modification the system may be'emlll@ frequency of the generator at the transmit,

ting statlon in any desirable manner either by means of varlable inductances as shown in Fig. l, or by means of variable condense'rs 27, as shown in Figx orby both.

It will be apparent, as shown, that it is preferable to have the earth plates 3 and 1 v of the receiving system in the same lstratuml 8 asl that in which the earth plates andfl of the transmitting system are buried.

Having now set forth the objects and na`` ture vof my invention and havingv shown and,

describeda construction, embodying the.

` vprinciples thereof, what I claim as new and i prising'a pair of overhead base lines each- .l lformed between plates buried in the earth in substantially the same stratum'of greater l conductivity than that of the earths surface,

vof said ase lines.

usefull and of my own invention and desire to secure by Letters' Patent is: v 1. A system of electrical signalling comprisin forme between plates buried in the earth in substantially the same stratum-of dii'erf ent conductivity from that of the earths surface, and a signalling circuit associated 4with each of said base lines. 2. A system offelectrical signalling comprisin aA pair of overhead base lines each forme between plates 'buried in'. the earth in'substantially the same stratum of greater and a si nalling circuit rassociated with each A system of electrical signalling comin substantially the same stratum of differentv conductivity from lthat of the earthls surface, and a signal transmittingand a signal receivin ystem respectively asso' ciated with sai base lines.

4. A system ofy electrical signalling lcom?.V a pair of loverhead base lines each prisi-n forme between plates buried inthe earth and a signal transmitting and asignal rea pair of overhead base lines each` e tum and ofv ceiving` systein respectively' associated .with said baselines. 5. 'AsyStem of. electrical `signalhng'f comprising-aJ paia` of overhead'base lines subf.

stantially parallel to each other, and widely separated, each of said base lines formed between plates widely separated and buried in the earth in substantially the same stratum and ofdill'erent conductivity from ythat "f `,of the earths surface, and a signallin -circuit associated with each` of saidbasej mes.

6. A system of electrical signallingy comprising a pair of overhead base lines substantially parallel to each other, and widely separated, each of said baselines formed between plates widely. separated andA buried Vin the earth in substantially the same stratum'- andv of greater conductivity than 'that ofthe earths surface, and a signallingcin cuit associated with each of said base lines.`

i 7.` A `system of .electricalsign'alling comprising a' "pair of overhead ybase lines'. substantially parallel to eachother, and widely .separated7 each of said base lines. formed between plates widelyl separated land buried in' the earth l in substantially the same straltum and of different conductivity from that ofthe earthsv surface, and a signal trans- ,inittingl and a signal ,receiving system respectively 'associated with said base lines.

. 8. A system of electrical signallingcomprising a pair of'overhead base lines substantially parallelesto each other, and widely separated, each` of said base lines formed1 vbetu'feen plates widely separated and buried inthe earth in substantially the same straofthe earth s surface, and ya "slgnal transjmitting and a'signal receiving system respectively associated with said. base lines.

f In testimony whereof I have hereunto` set Ay'hand lonthis 3lst day of 'May, A. D. 191

LEE DE FOREST.

reater `conductivitythan that 

